Sort and rinse lentils. Place lentils in a small saucepan; cover with water to 2 inches above lentils. Bring to a boil. Reduce heat; simmer 20 minutes or until almost tender. Drain.

Heat a large nonstick skillet coated with cooking spray over medium-high heat. Add chicken; cook 4 minutes on each side or until lightly browned. Remove chicken from pan. Add onion and ginger to pan; sauté 7 minutes or until tender. Add carrot and cardamom; sauté 2 minutes. Return chicken to pan. Add rice, lentils, rind, juice, salt, and pepper. Combine broth and saffron; stir until saffron is dissolved. Add saffron mixture to pan; bring to a simmer. Cover and cook 15 minutes or until rice is almost tender and liquid is absorbed. Stir in spinach. Remove from heat. Cover with a towel; place lid over towel. Let stand 10 minutes.